Metallic construction for aircraft and the like



cf'w. HALL.

March 1, 1932.

METALLIC CONSTRUCTION FOR ATRCRAFT AND THE LIKE Filed Aug. 26, 1929 2 Sheets-Sheet 1 A cam.

mvzmoa 3Z1) ATTORNEY March 1, 1932. c. w. HALL I 1,847,559

METALLIC CONSTRUCTION" FOR AIRCRAFT AND THE LIKE Filed Aug. 26, 1929 2 Sheets-Sheet 2 ZMQ W ATTORNEY Patented, Mar. 1, 1 932 UNITED" STATES CHARLES WARD -HALL, OF BUFFALO, NEW YORK METALLIC CONSTRUCTION FOR AIRCRAFT AND THE LIKE Application filed August-26, 1929. SeriaI'No. 388,408.

This invention relates primarily to a metallic construction, of the type shown and described in Letters Patent No. 1,609,468 issued tome under date of December 7 1926, in

which sheet metal, preferably duralu'min or other suitable aluminum alloy, is largely em- 'ployed and in which a framework of transverse and' longitudinal members is enclosed, in part or wholly, by a structural skin.

1 0 In constructions of this character, which are well adapted for such parts as the wings and fuselages of airplanes and the hulls of seaplanes and of light racing hydroplanes for example, it has heretofore been the practice to first assemble the framework and then to fit and attach the sheet metal skin by riveting it to the outer chords or flanges of the frame members, usually to the more closely spaced stringers or longitudinal members of 0 the frame. The riveting of the skin to the framework, however, is rather a tedious operation, requiring time and labor, and frequently is troublesome because of the difficulty of access to the work.

The principal object of my present invention is to simplify the Work, and so c'heapen the cost, of the construction; and this object I have attained by a new method of construction which, departing from the old procedure, consists, broadly stated, in attaching to the skin suitably positioned thereon 'one' set of the frame members, usually and preferably the longitudinal stringers, as the first'step in the operation and in then fitting and attaching these members, carrying the skin thereon, to the transverse frames or other such frame members. 7% r i The great advantage-of this method ofpro cedure is that the major part of the riveting required, for the attachment of the skin to the stringers, can be done on riveting machines or as a machine operation, and the 'specialhandwork required, for riveting the stringers in place on thetransverse frames, is not only less in amount thanformerly but is more accessible for the use of suitable portable riveting machines.

The invention also includes the novel features of structural detail hereinafter described and particularly pointed out in the appended claims.

For a full understanding of the invention and of-its several features, reference'is made to the accompanying drawings, in which 5 Figure 1 is a view showing, inperspective, a broken section of the hull of a sea-plane in process of construction; Fig. 2 is an enlarged perspective view of a clip for use in the attachment of the stringers to the ordinary n frames; and Fig. 3 is an enlarged detail, partly in side elevation and partly in section, of a jointure by which the tubular inner chord of a stringer is carried through a bulkhead. frame.

As here illustrated, the framework of the structure comprises a keel A, frames B, bulkhead frame B, and stringers C; and D indicates the structural sheet metal skin with which the framework is enclosed.

The sheet metal keel A, of truss construction, is stiffened along its lower outer edge by strips 1 riveted to its opposite sides, its cen-' 'tral or web portion is stiffened by riveting to the opposite sides thereof flanged semi-tubular web members or U-sections 2, and to its upper edge, provided with spaced notches 3 to receive the inner tubular chords of the frames, is attached a chord member 4 of flanged tubing which is riveted in place so after the frame chords have been'inserted in the notches therein and closes these notches.

Each of the frames B, also of sheet metal construction, is provided with a flanged g5 chord 5 around its outer edge, which edge is provided with spaced notches 6 to receive the inner tubular chordsof the stringers, and to its inner edge is riveted a continuous chord 7 of flanged tubing. The web portion and an outer flange of the frame is cut apart, Centrally of the bottom, to admit the keel and, wmenn rgpla'ce with its tubular chord resting on the bomn ofanptch inthe keel, these severed ends are securedmhekeelpy angles 98 8 or by flanges bent up from the web matfiial.\+

The bulkhead frame B, stiffened by flanged semi-tubular upright U-sections 9 riveted to its opposite sides, is provided with a double or T-fla-nge around its outer edge by 30.1

means of shaped angles 5* riveted thereto, and the flanges of the two sections of skin but is without notches in this edge, and on the opposite sidesof the keel with packaround the edge of a central opening, which ing and a U-shaped cover-strip are riveted toprovides a assageway therethrough and 1s gether through the keel, as in my prior patto be close in any suitable manner by a ent. At other points, adjacent sections of the water-tight door (not shown) is riveted a skin may be overlapped and joined, to form chord member 7 of flanged tubing. The keel a water-tight or other joint, in any suitable is, or may be, carried through the bulkhead manner. by slitting the plate (not shown) to recelve In the case of a bulkhead frame, the prethe web of the keel and joining the SldGS ferred practice is to carry the skin continuof the slit to the keel by angles similar to ously over its flanged edges, but to cut the the angles 8, and carrying the upper tubular stringers away, or to use stringer sections of chord of the keel, plugged at the polnt, a length, to provide a space 13 suflicient to through an opening provided therefor an permit the insertion of the flanges of the packing and closing the opening around the frame between the ends of the stringer-sec chord by a clip similar to the clips 11 by tions and then to carry the tubular chords which the stringers are attached to the ordlof the stringers through openings 14 in the nary frames, as hereinafter described. frame by a special jointure (see Fig. 3),

The stringers C are here shown as of bulb which is both water-tight and in efi'ect renangle form, with outer flange, a solld Web, ders the chords of the stringers continuous 35 and inner tubular chord. They are placed throughout. For this purpose a section of in position on the inner side of the sheet tub 15, which preferably is plugged cen metal skin D, or a section thereof, 1n sulttrally by acork or other stopper 16 and is abl spaced relationship to enable them to fit telescopically inserted within the tubularinto the spaced notches 6 in the frames and chord of one section of the stringer, is shifted their flanges are riveted to the skin, preferlongitudinally after the stringer is in place ably, as in my prior patent, with the heads through the opening in the bulkhead frame of the rivets countersunk in the outer surand through two shaped gland-rings 17, one face of the skin in conical depressions upset on each of the frame, and partially into the both in the skin and in the flanges of h tubular chord of the adjacent section of the stringers. As a matter of practice, it Wlll stringer. The flanges of the two rings are be found convenient to attach the stringers then riveted to ether, through the frame. to

edges of theframesand then shifted slight-- tallic skin. ly-therein to bring the body of the clips backs will abut against the side of the frames jects.

to the skin successively first positioning one compress a pac ing 18, of tow or other suitstringer and running the parts through a I'lV- able material, between the rings and tightly eting machine which will form the depresabout the tube. To reinforce the stringer at sions, punch the holes, and insert and set the this point, a short section of stringer 19 is rivets, and repeating the operatmn w1th each sprung over the stringer roper on each side successive stringer. of the bulkhead and is shi ted thereon as close The stringers having been secured toa secto the bulkhead as possible and then riveted tion of skin and the frames having previously in place both to the stringer and to the skin. 1 been attached to the keel, the stringers with The skin should be rivetedto the flanges of the skin thereon are fitted into the notches the angles around the bulkhead through an in the frames and there secured in place by interposed packing strip. suitable clips 10 (see Fig. 2), which are While I have described the several parts or may be shaped up from sheet metal to proas joined by rivets, I have done so simply bevide a circular flanged opening 11 adapted to cause I prefer to use rivets for joining to- .embrace the tubular chord of the stringers gether these parts when made of duralumin and two wings or ears 12 which straddle and or other similar alloys of aluminum, which are riveted to the web of the stringers, while cannot be successfully spot-welded, and it the body of the clip is riveted to the web of will be understood that any other means ll's the frame. The clips may be attached to the suited to the mgterielaisedmafifi l d stringers either before .or'afterthe stringers it is evident that the invention is adapted have been fitted into place in the notches of to constructions of the framed and enclosed the frames; but, where attached in advance or partially enclosed, parts of all classes of as here shown, the stringers will either have aircraft, and, generally, to all structures in to be fitted into the notches in position to aL which a metallic framework rigidly suplow the clips to pass'the flanges on the outer ports and is in turn strengthed by t.

It is alsotc'befiiderstood that the several features of the invention may be variously modified in their details and that one or more of these features may be used without the opposite that from which the flange proothers, within the scope of the appended The skin, on each side of, the keel, claims, without departing from the spirit or is bent downwardly to provide a flange 10, is sacrificing the advantages thereof.)

against the web of the frame, or, better, so attached that what maybe called theirflat porting the frames 'in position, positioning the stringers upon and securing them to the skin, fitting the assembled stringers and skin as a unit upon the frames, and attaching the stringers to the frames to permanently secure the frames in position and complete the framework.

2. In a metallic construction for aircraft and the like having a structural sheet metal skin enclosing at least partially a framework consisting of a series of transverse-- frames and a seriesof longitudinal stringers;

extending at right angles and without break of continuity over a plurality of the frames;'

the method of construction which comprises-- temporarily supporting the frames in position, positioning the stringers upon and securing them to the skin, fitting the skin and attached stringers upon the frames, and completing the structure by securing together the frames and stringers.

3. In a metallic construction for aircraft and the like having a structural sheet metal skin enclosing at least partially a primary framework of transverse frames and longitudinal stringers extending at right angles and without break of continuity over a plu rality of the frames, the method of construction which comprises temporarily supporting the frames in position, attaching a series of stringers to each of a plurality of skin sections. fitting the assemblage of stringers and skin sections upon the frames, permanently securing the frames in position by rigidly fastening the stringers thereto, and joining together the adjoining sections of the skin.

4. In a metallic construction for aircraft, and the like having a framework with-keel;

and transverse frames and longitudinal stringers and a structural skin, the process which comprises joining the keel and transverse frames, shaping up the stringers from sheet metal and attaching a series thereof to each of a plurality of skin sections, fittingthe assembled stringers. and skin sectionsjupon and attaching the stringers to the frames, and

joining together the adjoining'sections of theskin.

5. In a metallic construction for aircraft and the like having a framework of transverse frames and longitudinal stringers and a structural skin, the process which comprises attaching a series of stringers to a section of skin, then attaching aseries of clips tothe stringers, and attaching the said assembly to the frames by means of the clips.

6. In a metallic construction for aircraft and the like having a framework of transverse framesand longitudinal stringers and a structural skin, the process which comprises fastening the stringers to the skin in suitably spaced relationship thereon, then fitting the stringers into spaced slots provided therefor around the peripheries of theframes, and finally securing thestringers in place by clips.

7. In a metallic construction for aircraft and the like having a framework of transverse frames and longitudinal stringers of 1 bulb angle form and a structural skin, the process which comprises fastening the flanges of the stringers to the skin in suitably spaced relationship thereon, then fitting the inner bulb chords pf the stringers into spaced slots provided therefor around the peripheries of the frames and finall securin the strin ers in' place by clips encircling the bulb chords of the stringers and attached to the webs of both stringers and frames. s

8. The method of constructing a metallic structure framed by transverse frames, in-v cluding a bulkhead, and longitudinal stringers and at least partially enclosed by a structural skin which comprises attaching to a section of skin adapted to extend continuously over the bulkhead and adjoining frames on each side thereof a series of stringers suitably positioned thereon and cut away at the position of the bulkhead to admit the same, attaching the stringers with the attached skin to the frames other than the bulkhead, and joining the adjacent ends of the cut away stringers through openings in the bulkhead and sealing the openings around the stringers with a water-tight packing.

9. The method of constructing a metallic structure framed by transverse frames, in cluding a bulkhead, and longitudinal stringers of bulb angle section and at least partially enclosed by a structural skin which comprises attaching to a section of skin adapted 'to extend continuously over the bulkhead and adjoining frames on each side thereof the flanges of a series of stringers suitably positioned thereon and cut away at the position of the bulkhead toadmit the same, inserting the stringers thus attached to the skin in notches provided therefor'in the outer periphery of the frames other than the bulkhead and attaching them to said frames, and joining the adjacent ends of the cut away stringers through openings in the bulkhead by telescopically fitting the ends of sections of tubing passed through said openings into the ends of the tubular chords of the stringers and sealing the openings around the tubing with a water-tight packing.

10.- In a metallic construction of the type described, the method of connecting the tubular chord of two sections of one frame-memplate the' ends of two sections of a member provided with a tubular chord, a jointure for the .chord of the two sections comprising a section of tubing passing through an opening in the plate and telescopically fitted into the end of the chord of each of the two sections, and a water-tight packing sealing the opening in the plate around the tubing.

12. In a metallic construction having a plate and adjacent the opposite sides of the plate the ends of two sections of amember provided with a tubular chord, a jointure for the chord of'the two sections comprising a centrally closed section of tubing passing through an opening in the plate and telescopically fitted into the end of the chord of each of the two sections, and a water-tight packing sealing the opening in the plate around the tubing.

13. A sheet metal clip for metallic con structions of the type described having a body provided with a substantially circular I opening open at one side to the side of. the

body by a slit and, upset from the body on one side thereof, a flange surrounding said opening and providing substantially parallel ears along the sides of said slit. 7

14. In a metallic construction for aircraft and the like with a framework having a keel and transverse frames, the process of joining the keel and frames which comprises forming the lower chord and web of the keel, slot ting the upper edge of the Web of the keel at the frame positions to receive the upper chords of the frames, cutting apart the web and lower chord of the frames centrally to straddle the web "of the keel, fittingtogetlier the keel and frames, closing the slots in the web of the keel over the chords of the frames by attaching a chord member to the upper edge of the web of the keel, and joining the ends'of the webs of the frames to the web of the keel. I s

15.. In a metallic construction for aircraft and the'like having a frameworki with a keel andtransverse frames, 21. jointure between the keel and a frame in which the lower and upper ,chords' of the keel are continuous below and above the respective chords of the frame and the web of the keel is continuous through the web of the frame, the upper chord of the frame is continuous through an inserting a length of tubing passed opening therefor in the upper part of the CHARLES WARD HALL. 

